Design and Fabrication of a TiO&lt;sub&gt;2&lt;/sub&gt;/SiO&lt;sub&gt;2&lt;/sub&gt; Dielectric Broadband and Wide-Angle Reflector and Its Application to GaN-Based Blue LEDs

Lin, Nan-Ming; Shei, Shih–Chang; Chang, Shoou‐Jinn

doi:10.1109/jqe.2015.2439518

Cited by 7 publications

(1 citation statement)

References 17 publications

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“…Further, they suggested the application of a fabricated reflector for light trapping in the thin-film solar cell. Lin et al (2015) analyzed the reflector made-up of thin films of TiO 2 /SiO 2 prepared by the e-beam evaporation approach. The reflectance analysis using UV-Vis spectroscopy endorsed a maximum of 100% reflectance in the wavelength region between 390 and 650 nm [12].…”

Section: Introductionmentioning

confidence: 99%

Transparent Dielectric TiO2/SiO2 Coatings for Thermal Shielding and Self-Cleaning Applications

Yepuri¹,

R.S.²

2022

KJS publishes peer-review articles in Mathematics, Computer Sci

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The economical fabrication of one-dimensional dielectric reflectors using the hybrid sol-gel spin coating process is significant compared to sophisticated chemical and physical vapor deposition techniques. In this work, we opted for alternate layers of TiO2 and SiO2 films to fabricate near-infrared dielectric reflectors owing to their high refractive index contrast and easy tunability of the reflection window in the desired spectral range. X-ray diffraction (XRD) studies of the monolayer TiO2 and SiO2 confirmed the existence of anatase-TiO2 and amorphous-SiO2 phases, respectively. Spectroscopic ellipsometry investigation of TiO2 and SiO2 films revealed the refractive indices of 2.6 and 1.5, respectively. The field-emission scanning electron microscopy (FESEM) analyses evidenced the fabrication of 2.5 stacks/bilayers of TiO2/SiO2 (TiO2/SiO2)2.5S. The reflectance measurement demonstrated 100% reflection in the near-infrared region with its center wavelength of 833 nm. In addition, we have examined the water contact angle of various samples using the sessile drop technique, and 2.5 stacks-based reflector showed its lowest contact angle of 29.3o, which suggests its anti-fogging and self-cleaning applications.

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Section: Introductionmentioning

confidence: 99%

Transparent Dielectric TiO2/SiO2 Coatings for Thermal Shielding and Self-Cleaning Applications

Yepuri¹,

R.S.²

2022

KJS publishes peer-review articles in Mathematics, Computer Sci

View full text Add to dashboard Cite

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Micro/Nanoscale Optical Devices for Hyperspectral Imaging System

Huang

Zhang

2017

Outlook and Challenges of Nano Devices, Sensors, and MEMS

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A kind of graphene film metamaterial for terahertz absorbers

Gao

Ding

et al. 2016

Optoelectron. Lett.

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A kind of functional graphene thin film metamaterial on a metal-plane separated by a thick dielectric layer is designed for terahertz (THz) absorbers. We investigate the properties of the graphene metamaterial with different interlayers in the 0-3 THz range. The simulation results show that the absorption rate reaches up to 99.9% at the frequency of 1.917 THz. Changing the period to 80 μm×18 μm can get a narrow-band high quality factor (Q) absorber. We present a novel theoretical interpretation based on the standing wave field theory, which shows that the coherent superposition of incident and reflection rays produces standing waves, and the field energy is localized inside the thick spacers and dissipates through the metal-planes.Recent researches have demonstrated that graphene is an efficient terahertz (THz) modulator [1][2][3][4] . The optical properties of graphene have attracted particular interest in the metamaterial and plasmonic polaritons [5][6][7][8][9] . More recently, graphene-based metamaterials with perfect absorption have been theoretically and experimentally studied, including the effective surface conductivity investigations of graphene micro-ribbon metamaterials and structured graphene metamaterials [10][11][12][13][14] .In this paper, we design a perfect absorber based on graphene, and demonstrate that the perfect absorption can be achieved by the patterned graphene microstructural arrays on a thick spacer deposited on a reflecting metal substrate. Numerical simulations and analytical calculations are used to investigate the perfect absorption and the surface current resulting from a local energy field in the absorber induced by CST 2009 and a standing wave effect.We design a graphene metamaterial absorber with unit cell consisting of a graphene metamaterial and a thick dielectric interlayer deposited on the metal plane, as shown in Fig.1. One graphene micro-circle array and a metallic ground plane are separated by a thick dielectric spacer. The ground plane and the dielectric layer are copper metal and silicon (Si), respectively. The metagraphene has a radially periodic structure with period of 36 μm×36 μm, and the center of the circle is (0, 0). The Si dielectric with refractive index of n= d ε =3.45 is deposited on a copper metallic ground plane, and the thickness of Si dielectric spacer is d=33.4 µm. The copper metallic ground plate with conductivity of σ=5.9×10 7 S/m and thickness of t 2 =0.2 µm has perfect reflection property in the THz regime. The graphene is numerically modeled by a thin layer with thickness of t 1 =0.5 nm and permittivity of ε eff =1+σ s /ε 0 ωΔ (Δ=t 1 ), where σ s represents the conductivity of graphene, which can be derived using the well-known Kubo formula. The conductivity of graphene is described with interband and intraband parts as σ s =σ s intra +σ s inter , where σ s inter and σ s intra are interband and intraband conductivities, respectively. At THz frequencies, the photon energy is hω<

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Design and Fabrication of a TiO<sub>2</sub>/SiO<sub>2</sub> Dielectric Broadband and Wide-Angle Reflector and Its Application to GaN-Based Blue LEDs

Cited by 7 publications

References 17 publications

Transparent Dielectric TiO2/SiO2 Coatings for Thermal Shielding and Self-Cleaning Applications

Transparent Dielectric TiO2/SiO2 Coatings for Thermal Shielding and Self-Cleaning Applications

Micro/Nanoscale Optical Devices for Hyperspectral Imaging System

A kind of graphene film metamaterial for terahertz absorbers

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